JP2000252141A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure insulating property and improve assembling property by providing a coil part including a low voltage coil and a high voltage coil arranged in a bobbin and forming an insulation layer on the surface of a plurality of cores in a core part. SOLUTION: An E-shaped core 1 is comprised of a ferrite core, etc., in a core part 1A, and an insulation layer 1a with a thickness of 0.5 mm or less made of an insulative member such as ethyleneterephthalate resin, polyester resin, etc., which is superior in insulation property is formed over the entire surface of the core part 1A. The insulati on layer 1a is formed by electrostatically coating a resin material, or dipping a core 1 in a liquid resin material, taking it out therefrom, and drying and heating it thereafter. Furthermore, a liquid resin material may be sprayed with a spray gun, or the core 1 in the heating state may be dipped in a resin powder in the floating state, that is, so-called 'powder coating' is used to form the insulation layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transformer,
In particular, the present invention relates to an improvement in a transformer for generating a high-frequency high voltage for lighting a rare gas discharge lamp in which a pair of strip-shaped external electrodes is disposed on an outer peripheral surface of a glass bulb having a light emitting layer on an inner surface.

[0002]

2. Description of the Related Art The applicant has previously proposed a rare gas discharge lamp DL shown in FIG. The rare gas discharge lamp DL includes, for example, an envelope A made of a straight tubular glass bulb, and a light emitting layer B made of a phosphor such as a rare earth phosphor or a halophosphate phosphor formed on the inner surface of the envelope A. And a rare gas sealed in the inner space of the envelope A formed in a sealed state, and the first and second openings E1 and E2 on the outer peripheral surface of the envelope A over substantially the entire length thereof. A pair of strip-shaped external electrodes C and D spaced apart so as to form E2, and a light-transmitting light mounted on the outer peripheral surface of the envelope A so as to cover the external electrodes C and D. And the insulating member F.

In the rare gas discharge lamp DL, the light emitting layer B
Has an aperture portion Ba without a light emitting layer at a portion corresponding to the first opening portion E1, and light from the light emitting layer B is mainly transmitted through the aperture portion Ba to the first opening portion E1. Is released to the outside. The rare gas is a single gas or a mixture of a predetermined amount of xenon, krypton, neon, helium or the like which does not contain a metal vapor such as mercury. It is preferable to fill a rare gas containing xenon as a main component. Further, the insulating member F is made of, for example, polyethylene terephthalate (PE).
T) It is desirable to use a resin tube having heat shrinkability such as a resin. However, a resin sheet having an insulating property such as a PET resin or a polyester resin is wound and fixed to the envelope A using an adhesive layer. Alternatively, a light-transmitting glass bulb or the like having heat resistance can be attached to the envelope A.

The rare gas discharge lamp DL is lit by, for example, a lighting circuit TC shown in FIG. This lighting circuit TC
Is, for example, a high frequency high voltage (for example, a frequency of 25 KHz,
It is constituted by an inverter circuit for generating a voltage of 2500 V0 _-P ). The lighting circuit TC includes, for example, a transformer TR having primary coils TRa and TRb, a secondary coil TRc, and an exciting coil TRd;
A choke coil CH connected between a middle point of TRb and a DC power supply (not shown), and first and second switching elements connected to primary coils TRa and TRb, for example, first and second switching elements
It comprises second transistors Qa and Qb, and resistors Ra and Rb connected between the bases of the first and second transistors Qa and Qb and the exciting coil TRd. The external electrodes C and D of the rare gas discharge lamp DL are connected to the output side (secondary coil TRc) of the lighting circuit TC.

In this lighting circuit TC, a transformer TR, first and second transistors Qa and Qb, resistors Ra and Rb, etc. constituting an inverter circuit are mounted on an appropriate printed circuit board. It is configured to be easy to mount. For example, the transformer TR is configured as shown in FIGS. The transformer TR includes, for example, a core part 1 composed of a plurality of E-shaped cores and a coil part 2. The coil part 2 includes, for example, a bobbin 3 formed of a resin material having excellent electrical insulation properties. , The primary coils TRa and TRb and the exciting coil T disposed on the bobbin 3.
It comprises a low voltage coil 4a made of Rd and a high voltage coil 4b made of a secondary coil TRc. In addition,
For convenience of explanation, primary coils TRa and TR of transformer TR
b and the excitation coil TRd are the names of the low-voltage coils 4a,
The secondary coil TRc may be confused with the name of the high voltage coil 4b.

The bobbin 3 has, for example, a primary coil TR
a, TRb and a cylindrical portion 3a in which an exciting coil TRd and a secondary coil TRc are stacked or arranged side by side;
a plurality of flange portions 3 formed apart from each other at appropriate portions
b, 3c, 3d, first and second terminal blocks 3e, 3f formed at both ends of the cylindrical portion 3a, and pins arranged in the standing state on the first terminal block 3e so as to be separated from each other. Terminals P1, P
2, P3, P4, and P5, and pin terminals P6 and P7 that are arranged on the second terminal block 3f so as to be separated from each other in a standing state. The pin terminals P1 to P3 are connected to primary coils TRa and TRb, the pin terminals P4 to P5 are connected to an exciting coil TRd, and the pin terminals P6 to P7 are connected to a secondary coil TRc.

The above-mentioned transformer TR is mounted on a printed circuit board. In this printed circuit board, a wiring pattern including a conductive land portion is formed on one surface of an insulating substrate such as a glass epoxy resin, and a portion corresponding to the conductive land portion is formed from one surface to the other. (Through-hole) is formed in the surface of. Specifically, the transformer T
R is the other surface of the printed circuit board, the pin terminals P1 to P7 are inserted into the corresponding holes, and the flange portion 3 on the pin terminal side.
After the edge portions of the terminals b and 3d are placed so as to be in contact with the other surface of the printed board, the respective pin terminals P1 to P
7 and the conductive land portion are mounted by soldering.

In this lighting circuit TC, when a DC power supply is connected to the inverter circuit, the first and second transistors Qa and Qb are turned on and off at appropriate times, so that the secondary coil TRc of the transformer TR has the above-mentioned structure. Is generated and applied to the external electrodes C and D of the rare gas discharge lamp DL. Thus, unlike the discharge lamp using a hot cathode or a cold cathode, which is lit by one discharge path along the longitudinal direction of the envelope, the rare gas discharge lamp DL is different from the external electrodes C and D. During this period (in a direction substantially perpendicular to the longitudinal direction of the envelope A), an infinite number of discharge paths are formed, so that the lamp is lit in a striped state. In this state, the light emitting layer B is excited by the excitation line of the rare gas to emit light, and the light is transmitted to the aperture B.
a to the outside through the first opening E1.

In particular, since no mercury is used in the rare gas discharge lamp DL, the amount of light rises sharply after lighting, and the amount of light reaches almost 100% simultaneously with lighting. ing. For this reason, it is suitable as a light source for reading originals of OA equipment such as a facsimile, an image scanner, and a copying machine.

[0010]

Since the above-mentioned rare gas discharge lamp DL has a different structure from a general fluorescent lamp, it is necessary to apply a high-frequency high voltage to its external electrodes C and D. . For this reason, the secondary coil TRc of the transformer TR has, for example, a frequency of 25 kHz and a voltage of 25 kHz.
It is configured to generate a high frequency high voltage of 00V0 _-P . In addition, for example, M
When an n-Zn ferrite is used, the resistance between the primary coil TRa, TRb, TRd and the secondary coil TRc via the core 1 is small because the resistance value is as small as several tens to several hundreds Ω. The secondary coil TRc as the high-voltage coil 4b needs to have a structure having sufficient insulation properties with respect to the core 1 because of the possibility of dielectric breakdown.

Therefore, conventionally, the high voltage coil 4b
Since the insulating sheet S having excellent insulating properties is arranged between the outer peripheral surface of the core section 1 and the core portion 1, sufficient insulating properties can be secured.

However, the high voltage coil 4b is connected to the bobbin 3
After that, the insulation sheet S must be manually arranged between the outer peripheral surface of the high-voltage coil 4b and the core portion 1, so that there is a problem that the operation of assembling the transformer TR becomes complicated.

In addition, for example, when the core portion 1 is formed by abutment of two E-shaped cores, a gap for adjusting characteristics is formed between the magnetic legs of the E-shaped core to be abutted, and the gap is formed in the gap. In some cases, the gap paper G having a thickness corresponding to the gap length is arranged, but there is a problem that such arrangement is troublesome and causes an increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transformer capable of securing sufficient insulation between a high-voltage coil and a core with a relatively simple structure and improving the assemblability.

[0015]

SUMMARY OF THE INVENTION Accordingly, in order to achieve the above-mentioned object, the present invention provides a core section comprising a plurality of cores, a bobbin and a coil section including a low-voltage coil and a high-voltage coil disposed on the bobbin. Wherein the core portion is formed by forming an insulating layer on a surface of a plurality of cores.

According to a second aspect of the present invention, the insulating layer is formed on the entire surface of the core, and the thickness of the insulating layer is 0.5 m.
m, and the third invention is characterized in that the insulating layer is made of a resin material by electrostatic coating, dip coating, spraying,
It is characterized by being formed by any of powder coating.

Further, according to a fourth aspect of the present invention, the coil portion has a plurality of flange portions at appropriate portions of the cylindrical portion,
In addition, a low-voltage coil and a high-voltage coil are arranged on a cylindrical portion of a bobbin having a terminal block having pin terminals at both ends of the cylindrical portion.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a transformer according to the present invention will be described with reference to FIGS. still,
4 to 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. In this figure, the characteristic part of this embodiment is that the core portion 1A is formed by forming insulating layers 1a, 1a having excellent insulation properties on the entire surface of the plurality of E-shaped cores 1, 1.

More specifically, in the core portion 1A, the E-shaped core 1 is formed of a ferrite core or the like, and the entire surface thereof is formed of an insulating member having excellent insulating properties such as PET resin or polyester resin. The insulating layer 1a having a thickness of 0.5 mm or less is formed. In particular, the thickness of the insulating layer 1a depends on the voltage applied between the high voltage coil 4b and the core 1,
It is set appropriately based on the insulation performance of the insulating layer 1a, the size of the gap for adjusting characteristics formed between the cores, and the like.

The insulating layer 1a is formed by, for example, electrostatically coating a resin material, or by dipping and lifting the core 1 in a resin material in a liquid state, and then drying and heating the resin material. It is formed by spraying a resin material in a state with a spray gun, or by so-called powder coating (or fluid immersion coating) in which a heated core 1 is immersed in a resin powder in a floating state. Adoption of any of these formation methods is desirable,
Formation by other methods is also possible. For mass production, electrostatic coating, spraying, etc. are recommended.

According to this embodiment, since the insulating layer 1a is formed on the entire surface of the core 1, the core 1A is simply mounted on the bobbin 3 on which the low-voltage coil 4a and the high-voltage coil 4b are arranged. The insulating layer 1a is automatically interposed between the outer peripheral surface of the high voltage coil 4b and the core 1. Therefore, there is no need to manually arrange an insulating sheet or the like between them as in the prior art, and the assembling work can be performed efficiently.

In particular, when forming a gap for characteristic adjustment between a plurality of cores, if the insulating layer 1a is formed in advance so that its thickness becomes a value necessary for obtaining desired characteristics, A transformer TR having desired characteristics can be obtained simply by assembling the core section 1A and the coil section 2. Therefore,
Assembly workability can be improved.

Furthermore, if the insulating performance of the insulating member constituting the insulating layer 1a is enhanced, the thickness of the insulating member can be reduced, and the form of the transformer TR can be further reduced.

The present invention is not limited to the above-described embodiment. For example, the core portion may be composed of only an E-shaped core, or may be a combination of an E-shaped core and an I-shaped core or a king-shaped core. And two I-shaped cores can be combined. The bobbin terminal block is integrated with the flange,
Or besides being composed of a single body with a plurality of pin terminals planted,
It can be formed separately for each pin terminal, and the flange portion can be appropriately increased or decreased according to the number of low-voltage coils and high-voltage coils. In addition, the respective coils can be stacked in addition to being arranged side by side on the bobbin. Further, the bobbin may be configured so that it can be divided into, for example, two parts from the central portion of the cylindrical portion thereof.

[0025]

As described above, according to the present invention, since the insulating layer is formed on the entire surface of the core, the core is simply mounted on the bobbin on which the low-voltage coil and the high-voltage coil are arranged. An insulating layer is automatically interposed between the outer peripheral surface of the high-voltage coil and the core. Therefore, there is no need to manually arrange an insulating sheet or the like between them as in the prior art, and the assembling work can be performed efficiently.

In particular, when a gap for adjusting characteristics is formed between a plurality of cores, the insulating layer may be formed in advance so that the thickness thereof becomes a value necessary for obtaining desired characteristics.
A transformer having desired characteristics can be obtained simply by assembling the core and the coil. Therefore, the assembling workability can be improved.

Furthermore, if the insulating performance of the insulating member constituting the insulating layer is enhanced, the thickness of the insulating member can be reduced, and the form of the transformer can be further reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a transformer showing one embodiment of the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a part of the core part shown in FIG.
Is a sectional view of the core portion, and FIG. 4B is a sectional view taken along line XX of FIG.

FIG. 4 is a vertical sectional view of a rare gas discharge lamp according to a conventional example.

5 is a lighting circuit diagram of the rare gas discharge lamp shown in FIG.

FIG. 6 is a plan view of the transformer shown in FIG. 5;

FIG. 7 is a side sectional view of FIG. 6;

[Explanation of symbols]

 TR transformer TC lighting circuit P1 to P7 pin terminal DL rare gas discharge lamp 1A core part 1 core 2 coil part 3 bobbin 3a cylindrical part 3b to 3d flange part 3e first terminal block 3f second terminal block 4a low voltage coil 4b High voltage coil

Claims (4)

[Claims] 1. A core part comprising a plurality of cores, and a coil part including a bobbin and a low-voltage coil and a high-voltage coil disposed on the bobbin, wherein the core part has an insulating layer formed on a surface of the plurality of cores. A transformer characterized by being configured as follows. 2. The transformer according to claim 1, wherein the insulating layer is formed on the entire surface of the core, and the thickness of the insulating layer is set to 0.5 mm or less. 3. The transformer according to claim 1, wherein the insulating layer is formed of a resin material by any one of electrostatic coating, dip coating, spraying, and powder coating. 4. The bobbin having a plurality of flange portions at appropriate portions of the tubular portion and a terminal block having pin terminals at both ends of the tubular portion. 2. The transformer according to claim 1, wherein a low-voltage coil and a high-voltage coil are arranged.